Tornadoes · United States · Texas · 1981

F1 tornado, Llano County, Texas, October 13, 1981

This F1 tornado ran 1.0 miles across Llano County on October 13, 1981, touching down at 10:10 AM CDT and reaching 40 yards wide. It killed nobody, and did $5,000 to $50,000 of property damage.

The rating scale

Tracks are drawn in the color of the rating. The Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

  1. F040 to 72 mph

    Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

  2. F173 to 112 mphthis tornado

    Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

  3. F2113 to 157 mph

    Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

  4. F3158 to 206 mph

    Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

  5. F4207 to 260 mph

    Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

  6. F5261 to 318 mph

    Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

  7. Unrated

    The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating
F1
Date
October 13, 1981
Touchdown
10:10 AM CDT (15:10 UTC)
Path length
1.0 miles (1.6 km)
Path width
40 yards (37 m)
Deaths
0
Injuries
0
Property damage
$5,000 to $50,000
County
Llano County
Touchdown point
30.820, -98.830
Record number
749

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Stephenville/Cla, TX (KSEP), 12:00Z

3.2 hours before the tornado, 170 km from the path. October 13, 1981.

Skew-T log-pSkew-T log-p diagram, Stephenville/Cla, TX at 12:00Z on 1981-10-13Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 905 joules per kilogram, CIN 0, lifted condensation level 530 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Stephenville/Cla, TX at 12:00Z on 1981-10-13The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 184 square meters per square second, 0 to 6 km bulk shear 19 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
905 J/kg
Mixed-layer CIN
0 J/kg
Surface CAPE
1795 J/kg
Mixed-layer LCL
530 m above ground
0-6 km bulk shear
19 kt
0-1 km bulk shear
30 kt
0-1 km storm-relative helicity
184 m²/s²
0-3 km storm-relative helicity
221 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
5.7 K/km

Open this sounding in Storm Lab

Stephenville/Cla, TX (KSEP), 00:00Z

8.8 hours after it, 170 km from the path. October 14, 1981.

Skew-T log-pSkew-T log-p diagram, Stephenville/Cla, TX at 00:00Z on 1981-10-14Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel lifted from the surface. Mixed-layer CAPE 31 joules per kilogram, CIN -293, lifted condensation level 647 meters above ground. Wind barbs in knots down the right edge.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.
HodographHodograph, Stephenville/Cla, TX at 00:00Z on 1981-10-14The wind through the lowest 10 kilometers as a curve, rings every 10 meters per second labeled in knots. Zero to 1 km storm-relative helicity 37 square meters per square second, 0 to 6 km bulk shear 24 knots.193958Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.
Mixed-layer CAPE
31 J/kg
Mixed-layer CIN
-293 J/kg
Surface CAPE
68 J/kg
Mixed-layer LCL
647 m above ground
0-6 km bulk shear
24 kt
0-1 km bulk shear
11 kt
0-1 km storm-relative helicity
37 m²/s²
0-3 km storm-relative helicity
42 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0
0-3 km lapse rate
4.3 K/km

Open this sounding in Storm Lab

This ground now

The live radar over the trackEvery 1981 tornado in TexasEvery tornado in Texas since 1950Warnings in force in Texas nowThe forecast where you are

The other tornadoes of October 13, 1981

14 more were confirmed in the United States that day.

DateTimeRatingWherePath (mi)Width (yd)DeathsInjuriesDamage
October 139:00 AM CDTF3Navarro, TX7.21001$5,000 to $50,000
October 1310:00 AM CDTF1Henderson, TX6.250$5,000 to $50,000
October 1310:20 AM CDTF1Van Zandt, TX5.727$500 to $5,000
October 1312:27 PM CDTF2McLennan, TX2.01504$5 million to $50 million
October 1312:45 PM CDTF2Johnson, TX2.750$5,000 to $50,000
October 1312:50 PM CDTF1Johnson, TX0.110
October 131:00 PM CDTF1Johnson, TX5.750$500 to $5,000
October 131:00 PM CDTF2Hill, TX2.7100$5,000 to $50,000
October 132:30 PM CDTF1Tarrant, TX1.01002$5,000 to $50,000
October 132:40 PM CDTF1Dallas, TX1.050
October 133:15 PM CDTF1Hunt, TX5.673$5,000 to $50,000
October 134:00 PM CDTF1Lamar, TX0.110$50 to $500
October 134:30 PM CDTF2Lamar, TX6.650$5,000 to $50,000
October 137:00 PM CDTF1Choctaw, OK0.110

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.